281 results about "Polymer melt" patented technology

The present application discloses a continuous dynamic and efficient devolatilization method for a polymer / volatile system based on high mass transfer interfaces, including the following steps: providing a dynamic single-screw devolatilizer, feeding a polymer solution to the devolatilizer, wherein the polymer solution includes polymer and volatile substances with small molecule weight, and the volatile substances include organic solvents, residual monomers, water or reaction by-products; conveying and compressing polymer materials by the screw downstream a devolatilization section, and extruding the polymer materials out of the dynamic single-screw devolatilizer directly; or providing a side-feeding extruder downstream of the devolatilization section and feeding plastic additives into a devolatilized polymer melt, and then melt blending the plastic additives with the devolatilized polymer melt at an end of the dynamic single-screw devolatilizer before exiting the dynamic single-screw devolatilizer.

The invention discloses a multi-cooling molding method of a PVC (polyvinyl chloride) material, which comprises the following steps: S1, heating PVC resin and additives to a molten state, S2, extruding the molten polymer melt through a molding device to form a tubular blank; s3, the tubular blank is subjected to a first cooling stage, and a compact inner layer structure is formed; s4, the pipe blank with the solidified inner surface enters a second cooling stage, secondary cooling is conducted through cold air at the preset low temperature, and a tough outer layer structure is formed; s5, the pipe blank subjected to multiple cooling is subjected to shaping treatment; by means of the multiple cooling technology of inner and outer staged cooling, differential control over the inner layer and the outer layer of the pipe blank is achieved, the performance limitation caused by the single cooling mode in the traditional technology is overcome, the compact high-strength inner layer is formed, the pressure resistance and abrasion resistance of the pipe are enhanced, the cracking resistance of the pipe is improved, and the overall performance of the PVC pipe is effectively improved; and the application range of the PVC pipe is widened.

The invention discloses a synchronous temperature control method for co-extrusion molding of a multilayer polymer film, and relates to the technical field of high polymer material processing, and the method comprises the following steps: setting a target temperature interval of each polymer layer of the multilayer polymer film, and according to the melting characteristics, heat sensitivity and interface bonding requirements of each layer of material, setting a target temperature interval of each polymer layer of the multilayer polymer film; respectively determining an extrusion temperature set value and an allowable fluctuation range; through layered independent temperature control and preheating matching, thermal behavior synchronization of multiple polymer melts is achieved, and the interface bonding stability is improved; through a die head heat insulation and buffer structure, interlayer heat interference is effectively shielded, and the integrity of a functional layer is guaranteed; through the intelligent closed-loop temperature control system, the state of each temperature control area is predicted and adjusted in real time, and self-adaptive optimization of thermal control is achieved. And the co-extrusion quality, the consistency and the production intelligent level of the multi-layer film are integrally improved.

The invention discloses a novel textile material with eiderdown wrapped by rainbow yarn nanofibers and a preparation method. The novel textile material comprises skeleton fibers located at the axis, an eiderdown component with a heat preservation effect and a rainbow yarn nanofiber reinforcing layer wrapping the outer surface of the eiderdown component. The wrapping reinforcing layer is of a three-dimensional network structure formed by continuous or quasi-continuous nanofibers in a winding, interweaving and lap joint mode, so that stable compounding and structural shaping of down feather components and skeleton fibers are achieved under the condition that the down feather components and the skeleton fibers do not depend on adhesive fixation. The preparation method comprises the following steps: cleaning, drying and opening down for pretreatment; performing melt differential electrostatic spinning on the polymer melt under a high-voltage electrostatic field to form rainbow yarn nanofibers; the down flocs are introduced into the coating area through the framework fibers, so that the rainbow yarn nanofibers are deposited and wound to form a coating reinforcing layer; after being gathered and shaped and twisted into yarns, the yarns can be continuously dragged and wound. The novel textile material has spinnability, structural stability and long-acting thermal insulation performance, and is suitable for spinning, weaving and knitting processing.

The invention discloses a method for manufacturing an injection-molded receiver net plastic part, which comprises the following steps of: heating and melting a polymer melt through a feeding structure, injecting the polymer melt into a mold to obtain the receiver net plastic part, and quickly cooling a sound outlet hole of the receiver net plastic part by adopting preset high-temperature circulating liquid cooling in a first cooling stage through dynamic cooling treatment; the rigidity of the micropore area is effectively improved, the problem of micropore structure deformation caused by non-uniform cooling is reduced, polymer melt in the sound outlet hole area can be cured in time through rapid cooling, excessive shrinkage is avoided, and therefore the total shrinkage rate of the sound outlet hole is remarkably reduced; and in the second cooling stage, cold air is sprayed at the preset low temperature to slowly cool the outer surface of the receiver net plastic part, the toughness of the outer layer structure is enhanced, the differentiated cooling modes are accurately regulated and controlled according to different requirements of the inner and outer structures of the receiver net plastic part, uniform distribution of the shrinkage rate in the whole cooling process is achieved, and the product quality is improved. The problem that the overall shrinkage rate is too large due to a traditional cooling mode is effectively solved.

A cable (102, 510) has a functional core extending in a longitudinal direction and a sheath (524) surrounding said core such that an outer surface of said sheath forms an outer surface (532) of the cable. The outer sheath is formed around the core by extrusion (722) from a polymer melt. An outer part (726) of the extrusion tooling is maintained at a temperature lower than the melting point of the polymer by such an amount that an irregular texture is continuously imparted to the outer surface (532) of the cable. A miniature fibre optic drop cable made in this way can be delivered more than 250 m through a microduct by pushing alone, without the need for blowing equipment.

A polymer melt candle filter having a support which comprises a hollow cylindrical body defined by a first end, a second end, and a cylinder wall having a first end portion and a second end portion. The first end portion includes a screw thread on its outside surface and optionally a hex fitting on its inside surface for receiving a hex wrench. The second end portion includes a plurality of holes in the cylinder wall. The area of the openings of the holes on the outside surface of the cylinder wall may be larger than the area of the openings of the corresponding holes on the inside surface of the cylinder wall. The shape of the openings of the holes on the outside surface may be non-circular. A polymer melt filter plate assembly which comprises (a) a support plate comprising a plurality of threaded holes; (b) at least one filter which is screwed into at least one of the threaded holes via the screw thread on the outside surface of the first end portion of the filter support; (c) a tie rod with (i) a first end extending through a hole in a cone insert and a cap located at the second end of the filter support, and (ii) a second end extending through a threaded hole in the support plate; and (d) a cross bar which is attached to the second end of the tie rod for holding the support plate inside a shaft of an apparatus for filtering a polymer melt.

The invention discloses a supercritical fluid assisted polymer devolatilization distributor. The supercritical fluid assisted polymer devolatilization distributor comprises a gradually-shrinking channel, a throttling channel and a gradually-expanding channel which are connected in sequence. A static mixer is arranged in the throttling channel, the upstream pressure is maintained to be above a supercritical state by increasing fluid resistance, meanwhile, the mixing effect of supercritical fluid and polymer melt is enhanced, stable and uniform foam flow is formed, and pressure fluctuation is avoided; an automatic pressure relief valve assembly is arranged on the upper portion of the divergent channel and composed of a valve opening, a valve cover plate, a spring, an adjusting knob and the like, when the system pressure exceeds a set value, exhaust is automatically started, and controllable pressure relief is achieved. A plurality of rows of flow distribution holes are formed in the lower part of the distributor to ensure that the melt uniformly flows out to form stable melt strips; the problems that traditional equipment is difficult to pressurize and not timely in pressure relief are solved, the supercritical state maintenance, gas-liquid separation and melt forming processes are optimized, the volatile component removal efficiency is improved, the phenomenon that melt strips are broken or accumulated is effectively prevented, and continuous and stable operation of the devolatilization process is guaranteed.

The invention discloses a continuous polyester ring stirrer, a manufacturing method and a high-viscosity polymerization reaction kettle, and belongs to the technical field of stirring equipment. The continuous polyester ring type stirrer mainly comprises a grid cylinder provided with a plurality of film hanging holes, and a ring piece is fixed on the inner wall of the grid cylinder; the first circular ring piece located at the low-viscosity end D of the grid barrel is a perforated circular ring piece; and retention circular ring sheets are sequentially arranged on the inner wall of the grid cylinder body at intervals from the perforated circular ring sheets to the G direction of the high-viscosity end of the grid cylinder body. The continuous polyester ring stirrer is manufactured by adopting a production mode of double-region zoning concentric feeding. According to the stirrer disclosed by the invention, polymer melt is retained without material accumulation, the film formation area is large, the film formation effect is good, small-molecule by-products are quickly volatilized, and the polymerization reaction efficiency is high; the manufacturing method is efficient and low in cost, and the manufactured product is high in quality. And the method is of great significance in improving the whole machine quality of the high-viscosity polymerization reaction kettle and simplifying the later maintenance work of the whole machine.

The present invention related to a method of for the production of textile articles, I which the textile articles can be disassembled automatically or semi-automatically, in which, when sewing or stitching, a polymer melt yarn is used.

The invention discloses a branched polyolefin material modified hot melt adhesive. The hot melt adhesive comprises the following components: 40-60 parts of an ethylene-vinyl acetate copolymer, 20-40 parts of a branched polyolefin-acrylate copolymer, 2-20 parts of a branched polyolefin material, 5-30 parts of tackifying resin and 2-20 parts of a viscosity modifier, the branched polyolefin-acrylate copolymer is prepared from a bromine-containing branched polyolefin material and an acrylate monomer through a polymerization reaction; the bromine-containing branched polyolefin material is prepared by carrying out polymerization reaction on ethylene or ethylene and C3-C5 olefin and a bromine-containing monomer; the branched polyolefin material has a long and short branched chain structure, the weight-average molecular weight is 800-500000g / mol, and the branching degree is 50-220 / 1000C. The polyethylene-acrylate multipolymer with high branching degree is designed and combined with a branched polyolefin material, so that the melt flowability of the polymer is improved, the wettability of the surface of an adhered object is enhanced, the adhesive strength and the tensile strength are enhanced, the flexibility and the temperature resistance are improved, the shear strength and the peel strength are remarkably improved, and particularly, the heat resistance is remarkably improved; the device is suitable for high-temperature working environments.

The invention belongs to the field of polymeric high-molecular polymer production equipment, and relates to a final polycondensation reactor for preparing a high-quality and high-viscosity PA66 polymer, the final polycondensation reactor comprises a shell and a stirring device located in the shell, and the shell is provided with a feed port, a discharge port and a gas phase port; the shell comprises an inner layer and an outer layer, and an area between the inner layer and the outer layer forms a jacket layer; the inner layer of the shell is composed of a cylinder I and a cylinder II, and the diameter of the cylinder I is larger than that of the cylinder II. One bottom surface of the cylinder I and one bottom surface of the cylinder II are intersected and overlapped areas are communicated with each other; the position of the feed port is higher than that of the discharge port; the stirring device consists of a transmission shaft and a stirrer; the first stirrer consists of a disc and a spiral belt fixed on the disc; the second stirrer comprises a spiral structural member; and the third stirrer comprises a spiral propeller. According to the invention, the continuous propulsion of the polymer melt in the final polycondensation process is realized, the backmixing of the high-viscosity polymer melt is prevented, and the retention time consistency of the polymer melt is improved.

A method for molding a magnetic material into a rotor stack, including providing a polymer melt including magnetic compound particles and a polymer binder, providing a rotor including a plurality of cavities, the rotor being arranged in a mold having a mold cavity surface, and providing a gap between the outer periphery of the rotor and the mold cavity surface. The method also includes filling a first volume of the polymer melt into the cavities of the rotor at a first pressure and filling a second volume of the polymer melt into the rotor at one or more second pressures, the one or more second pressures being less than the first pressure and above an ambient pressure.

The utility model relates to a profiled fiber, and relates to the technical field of fibers. The profiled fiber comprises a flat sheet type fiber, and the profiled fiber is prepared from a high polymer melt with high viscosity. According to the profiled fiber, the cross section shape of the fiber is changed, and the specific surface area of the fiber is greatly increased, so that the profiled fiber has a relatively strong cool feeling effect.

The invention relates to a polypropylene hydrophilic modification method, an obtained material and a container cover prepared from the material. The hydrophilic modification method of the polypropylene comprises the following steps: uniformly mixing the components of the raw materials; adding the mixture into a double-screw extruder for melt grafting; and cooling the polymer melt extruded by the twin-screw extruder with water to obtain solid polymer strips, drying the polymer strips, and granulating to obtain hydrophilic polypropylene particles, namely the hydrophilic polypropylene composite material. The high-performance hydrophilic polypropylene composite material disclosed by the invention has excellent mechanical properties, the hydrophilic performance is also greatly improved, and the preparation process is simple. According to the container cover made of the material, the problems that water drops adhere to the container cover due to water vapor condensation and water drops scatter when the container cover is opened can be solved, the water drop phenomenon is improved into the water film phenomenon, the water drops scatter when the container cover is opened is avoided, the volatilization speed of water on the surface of the container cover is increased, and therefore the use dryness is enhanced, and the use experience of a user is improved.

The invention provides a plastic mold intelligent optimization system and method based on digital twinning. The method comprises the steps that a digital twinning model integrating mold cavity geometry and an injection molding machine hydraulic device is established; time sequence data of cavity pressure and screw movement in the filling and pressure maintaining stage are used as input, and PVT characteristic parameters and melt leading edge viscosity attenuation coefficients of the polymer melt in the current production period are identified and updated on line; on the basis of the PVT characteristic parameters and the melt front edge viscosity attenuation coefficient, predicting and generating a dwell pressure curve required for achieving a predefined cavity pressure balance curve in the next period; in the pressure maintaining stage of the next production cycle, the amplitude of the pressure maintaining pressure curve is adjusted according to the dynamic deviation of the cavity pressure detected in real time and the cavity pressure balance curve, a compensation control signal is output to an injection molding machine executing mechanism, and self-adaptive closed-loop adjustment of the cavity pressure is achieved. Based on the above scheme, feedforward optimization based on material characteristics and feedback control of AI disturbance can be realized.

The present invention relates to the technical field of foaming materials. Disclosed are a TPU supercritical foaming material and method for fabricating midsoles in footwear. According to the key points of the technical solution, the foaming material comprises the following raw materials in parts by weight: (1) 40-80 parts of polyol; (2) 20-50 parts of isocyanate; (3) 4-12 parts of a chain extender; (4) 0.1-30 parts of a modifier; and (5) a supercritical gas. The method for fabricating footwear midsoles from said raw materials comprises the following steps: S1, mixing, in the described parts by weight, the polyol, the isocyanate, and the chain extender, and compounding the resulting mixture in a twin-screw extruder to obtain a polymer melt; S2, preparing a supercritical gas by means of a gas inlet system, and then injecting the supercritical gas and the polymer melt into a single-screw extruder to prepare a molten mixture containing the supercritical gas; and S3, injecting the molten mixture into a mold, leaving it to stand, and then opening the mold to obtain the product.

The invention discloses a preparation method of superfine ES fibers, and relates to the technical field of ES fibers. S-acetyl-L-glutathione and silver nitrate are subjected to a coordination reaction to form a net-shaped structure with silver as a central ion, the effect of slowly releasing silver ions is achieved, the overall thermal stability and antibacterial performance are improved in cooperation with the sulfur element, and meanwhile the hygroscopicity is remarkably improved through amino groups in the net-shaped structure and a molecular chain; melting and mixing with polyethylene to form a skin layer, taking polyethylene glycol terephthalate as a core layer, and carrying out high-voltage static-assisted melting and spinning to uniformly refine polymer melt-jetting jet and improve tensile breaking strength and hygroscopicity; three drafting machines are used for drafting twice, and the fibers are fine-drawn again, so that crystal grains in the fibers are ordered, the heat shrinkage phenomenon during production is reduced, and the mechanical strength and the air permeability are improved; finally, the superfine ES fibers are obtained through relaxation, drying and cutting, and the effects of high strength, good hygroscopicity and antibiosis are achieved.

A hot runner injection nozzle system for use in co-injection molding with a built-in obturator valve (7) in a nozzle tip assembly (16) attached to a nozzle body (1) and permits several different directions of gating. It allows for independent flow of each melt stream having their confluence at the very last possible position avoiding mutual contamination with the built-in obturator (7). The nozzle tip assembly comprises several channels providing for the flow of multiple polymeric melt streams and an obturator that serves as a check valve. Selective flow of each stream is fully controlled by individual injection units at the source providing the feed for each melt stream. The invention allows for simple fabrication, maintenance, reduces mutual contamination and allows for a more compact hot runner manifold and tool design. It allows for an optional needle-valve when the product requires a better injection point finish.

The utility model discloses an electromagnetic heating device for spinning melt processing, which comprises a thermal insulation outer cylinder, a lining cylinder, an electromagnetic coil and a blanking cylinder, the lining cylinder penetrates into the middle of the interior of the thermal insulation outer cylinder, the electromagnetic coil for heating is wound on the outer wall of the lining cylinder, two ends of the electromagnetic coil are connected with a connecting lead connected to a circuit, and the blanking cylinder is connected with the connecting lead. The lower end of the lining cylinder communicates with a discharging cylinder, a connector is fixed to the upper end of the lining cylinder, and a melting pipeline is embedded in the middle of the inner wall of the connector. When the electromagnetic heating device for spinning melting processing is used, the electromagnetic coil is connected to the outer wall of the melting pipeline, the electromagnetic coil is powered on to generate a high-frequency magnetic field to heat the melting pipeline, polymer melt passing through the melting pipeline is melted so as to meet the processing requirement of the polymer melt, and the device adopts electromagnetic heating and is fast in temperature rise, accurate in temperature control and not prone to damage.

The invention provides a polylactic acid composite material and a preparation method thereof. The polylactic acid composite material is prepared from the following components in parts by weight: 70 to 90 parts of polylactic acid, 10 to 30 parts of elastomer, 5 to 6 parts of gas-phase nano filler and 0.1 to 0.5 part of antioxidant, wherein the specific surface area of the gas-phase nano filler is 200-380m < 2 > / g, and the number of surface hydroxyl groups is 2.02-3.37 / nm < 2 >. According to the invention, the gas-phase nanofiller with a specific specific surface area range and a specific number of hydroxyl groups is selected, and the characteristic that the gas-phase nanofiller spontaneously aggregates in a polymer melt to form a network is utilized to drive elastomer droplets to agglomerate in a polylactic acid matrix to form a special'bicontinuous-like structure '; the toughness is greatly improved while the rigidity of the composite material is ensured, so that the rigidity-toughness balance of the composite material is realized.

The invention relates to the technical field of non-woven material manufacturing equipment, in particular to a negative pressure drafting melt-blowing spinning device which comprises a box body, a screen, a melt heating mechanism, a receiving mechanism and a negative pressure mechanism. A micro-channel and a negative pressure channel are formed in the box body; the screen is used for receiving and transferring the molten polymer; the melt heating mechanism is arranged towards the screen; the receiving mechanism is used for receiving fibers; and a negative pressure channel is communicated with the box body, a negative pressure environment is provided for the interior of the box body, and the molten polymer is drafted through the micro-channel. A negative pressure environment is formed in the box body through the negative pressure mechanism, local negative pressure is provided below the screen through the slits formed in the inner sides of the micro-channels, and under the gravity and negative pressure conditions, drafting of molten polymers is achieved, and melt is drafted through the negative pressure, so that the recoil effect of the screen on positive pressure airflow in the prior art is reduced, and the drafting effect is improved. Meanwhile, negative pressure can be used as main drafting force, and stable and continuous preparation of the micro-nano fibers is achieved.

The invention belongs to the technical field of foam materials, and particularly relates to a pressure-resistant anti-aging composite foam box and a manufacturing method thereof. The method comprises the following steps: S1, preparing raw materials containing polypropylene and modified polypropylene; s2, mixing the raw materials, and performing melt blending granulation to obtain a modified polypropylene composite material; s3, the modified polypropylene composite material is fed into a hopper of a microcellular foaming injection molding machine to be preheated to be in a plasticized state, and then supercritical carbon dioxide is injected to serve as a foaming agent; s4, the polymer melt containing the supercritical carbon dioxide is injected into a cavity of the box forming mold with the preset temperature for pressure maintaining; the volume of a mold cavity is increased by controlling a mold core on one side of the movable mold to retreat, so that the pressure in the polymer melt is reduced, a foaming body is formed, and the target polypropylene composite foam box body is obtained after cooling and curing. The pressure-resistant anti-aging composite foam box prepared by the method disclosed by the invention has excellent buffering property, pressure resistance, aging resistance and environmental protection property.

The invention discloses a flash evaporation polyolefin conductive film as well as a preparation method and application thereof, and relates to the technical field of flash evaporation breathable films. The preparation method comprises the following steps: calcining a carbon nanotube, modifying with hexadecyl trimethyl ammonium bromide, preparing conductive master batches from the polymer melt A, a coupling agent and the modified carbon nanotube, and preparing the thin film from a spinning solution containing the polymer melt B, the conductive master batches and a spinning solvent through flash spinning equipment. According to the preparation method, the carbon nanotubes can efficiently adsorb hexadecyl trimethyl ammonium bromide to form a molecular wrapping layer, so that uniform dispersion of the carbon nanotubes in a spinning solution is promoted, the conductivity uniformity of the prepared thin film is guaranteed, the carbon nanotubes are of a curled round tube morphology structure, the porosity of the thin film is improved due to dispersion of the carbon nanotubes in the thin film, and the conductivity of the thin film is improved. The air permeability of the film can be highly maintained, and the prepared film is high in conductivity and hydrophobicity, can replace carbon paper to prepare a film electrode gas diffusion layer, and is low in cost.

This invention discloses an extrusion device for outer protective tubes of buried cables, relating to the field of cable outer protective tube production technology, aiming to solve the problem of easy delamination in traditional double-layer co-extrusion structures. The key technical points are: for producing cable outer protective tubes with reinforced structures, the device includes a first extruder, a second extruder, and a forming die head; the forming die head is located at the discharge port of the first and second extruders. The first extruder provides a first polymer melt to form the tube matrix, and the second extruder forms a second polymer melt with reinforcing material. This invention, through the cooperation of a rotating mandrel and a tangential injection hole, allows the reinforcing melt to dynamically embed into the inner wall of the matrix in a helical trajectory, forming a continuous helical reinforcing rib structure. This structure significantly improves ring stiffness and resistance to external pressure without significantly increasing wall thickness and weight, and because of the one-piece molding, it solves the problem of easy delamination in traditional double-layer co-extrusion structures.

Process and apparatus for processing of polycondensates, in particular for recycling processing of contaminated polycondensates, comprising the following processing steps: a) initially charging the polycondensates / materials to be processed, in particular in a container, b) at least partially, especially completely, melting the polycondensates, in particular by extruding in an extruder, and preparing a polymer melt, c) mixing the polymer melt, d) cooling the polymer melt, e) treating the mixed and cooled polymer melt in a melt reactor, in particular for polycondensation / postcondensation, to increase the intrinsic viscosity and / or to purify the polymer melt.

The present invention discloses a polymer molding detection device based on piezoelectric-thermocouple array and optical integration, wherein the basic components include: a measurement channel, an outer edge layer, and an insulating sleeve arranged coaxially from the inside to the outside; the measurement channel is a microarray structure channel, in which the polymer melt flows axially; the temperature control component includes a heating coil and a cooling water channel, the heating coil is arranged on the outside of the outer edge layer, and the cooling water channel is arranged in the outer edge layer; the microarray component includes two thermocouple sensor arrays and two piezoelectric sensor arrays of equal thickness; the two thermocouple sensor arrays are arranged relatively on the surface of the inner wall of the measurement channel, the piezoelectric sensor array and the thermocouple sensor array are arranged in a stacked manner, and the positions of the two piezoelectric sensor arrays are relative; the optical axis of the optical-stress measurement component is perpendicular to the axis of the measurement channel, and the internal stress of the polymer melt is detected by polarized light and a CCD camera. The present invention can realize the detection of global polymer melt information in the micro-molding measurement channel.

The invention discloses a PET polyester spinning system and application thereof, the system comprises a polyester subsystem and a spinning subsystem, the polyester subsystem comprises an ethylene glycol evaporator, an ethylene glycol conveying pipeline, a first melt conveying pipeline and an ethylene glycol evaporation heat medium circulating pump; the spinning subsystem comprises a second melt conveying pipeline, a melt booster pump, a melt cooler, a melt cooling heat medium circulating pump and a third melt conveying pipeline; one end of a circulating low-temperature secondary heating medium supply pipeline of the heating medium serial connection pipeline is communicated with the ethylene glycol heating medium circulating pipeline, and the other end is communicated with the melt heating medium circulating pipeline; one end of the circulating low-temperature secondary heating medium return pipeline communicates with the ethylene glycol heating medium circulating pipeline, and the other end of the circulating low-temperature secondary heating medium return pipeline communicates with the melt heating medium circulating pipeline. By recycling the waste heat in the PET polymer melt conveying process, the environment of a spinning production workshop is improved, and the use amount of a heating medium for primary heating of an ethylene glycol evaporation system is reduced, so that energy conservation and consumption reduction are realized, and the green, low-carbon and environment-friendly effects are achieved.

The invention discloses double layered delayed-release hard capsules made by double dipping, that is by two consecutive dip molding steps on the same mold pin without removing the film, provided by the first dip molding step, from the mold pin between the two dip molding steps, but dipping the mold pin with this first film in the second dip molding step, each dip molding step is done with a different polymer melt, providing a double layered delayed-release capsule.

A method of producing a linear fibrous structure in an alternating electric field by spinning of a polymer solution or polymer melt on a spinning electrode, in which nanofibers are formed from the polymer solution or melt in a spinning area created on the spinning electrode and are carried away from it by the action of the electric wind. In the spinning area, a narrow flat linear structure of polymer solution is formed with a finite length. The spinning area is open in the spinning direction and in the central part thereof. The nanofibers are formed and move away from the spinning area in a flat structure in which they gradually lose their kinetic energy. In a place with zero kinetic energy, nanofibers form a linear virtual collector in which nanofibers are formed into a ribbon of nanofibers.